In encapsulated measuring arrangements, it is necessary to provide a slot in the housing through which an entrainment member can protrude into the housing, in order to connect the structural unit, which is located there with the installation pedestal which is disposed externally of the housing in order to probe a measuring embodiment or scale. In case of relative motion of, for instance, the bed or base and the trolley of a machine, the movement of the machine transferred to the measurement graduation of the measuring embodiment or the structural unit to be probed, wherein the entrainment member is relatively moved in the direction of the motion inside the slot and the movement is measured.
The slot in the housing must be sealed as tightly as possible for protecting the highly sensitive scale, and a possibility for passing the entrainment member inside the housing, must solely exist in the region of the entrainment member.
Such a measurement arrangement is shown in DE-PS 28 46 768, wherein a scale and a probing unit are placed inside a housing, which comprises a slot which is continuous in measuring direction, which is closed by means of sealing elements which are disposed in a roof-shaped manner in the form of plastics or rubber lips, and through which an entrainment member passes in order to connect the probing unit with the object which is to be measured.